The impact of uranium ore grade on the greenhouse gas footprint of nuclear power

Abstract

Abstract A life cycle assessment of nuclear power production based on the uranium nuclear fuel cycle has been carried out, with greenhouse gas (GHG) emissions as the environmental impact of interest. The study focussed mainly on the once-through cycle with current technologies. The present life cycle-based GHG emissions of nuclear power production for a uranium ore grade of 0.15% U3O8 was estimated to be in the order of 34 kg CO2e/MWh, which is significantly less than for fossil fuel-based electricity. However, expected falls in uranium ore grade over time will narrow this gap due to the additional amount of ore that must be mined and processed in order to extract the same amount of uranium. This effect of uranium ore grade was examined in some detail, with the greenhouse gas footprint increasing to 60 kg CO2e/MWh when the ore grade falls from 0.15% to 0.01% U3O8. Projections indicate that the average ore grade of the world's uranium resources will fall to this level in about 50 years. Should the contribution of nuclear power to global electricity generation increase significantly beyond that expected over this period, these lower ore grades and associated higher greenhouse gas footprint would be reached much sooner. While the impact of new and improved technologies anticipated in the future in the various stages of the nuclear fuel cycle will help offset the effect of falling uranium ore grades in the near to medium term, the long-term future of nuclear power as a low greenhouse gas source of electrical power would appear to be strongly dependent on the widespread deployment of fast breeder reactors which will significantly increase the lifespan of current uranium resources. However, extrapolating results based on current resource and ore grade data into the future is fraught with uncertainties, and is done here to give indicative rather than definitive values for future uranium ore grades and the likely impact on the GHG footprint of nuclear power.